Fiberglass batt installation typically requires the time consuming cutting up or shaping of batts when the need arises to fill abnormally shaped open cavities between studs, or insulate around electric boxes, wires, and the like. Furthermore, structures insulated with batts often suffer from less than desirable thermal and sound insulation due to the void areas sometimes found around the edges of the batts adjacent studs or other supporting structure.
In recent years, a number of loose-fill insulation systems have been developed in an attempt to overcome these disadvantages inherent in residential fiberglass batt usage. In order to get low density loose-fill fiberglass insulation into enclosed vertically extending residential wall (stud bounded) cavities in a practical manner and at a commercially acceptable cost, it has heretofore been known to resort to the BIBS (Blown-In-Blanket.TM.) system disclosed, for example, in U.S. Pat. Nos. 4,712,347 and 5,287,674 to Sperber. Many residential contractors and the like currently use BIBS instead of fiberglass batts for the purpose of improving insulative qualities (both thermal and sound) and application efficiency.
In accordance with BIBS, a supporting structure such as flexible netting (e.g. nylon) or the like is affixed across a plurality of wall studs in order to enclose vertically extending wall stud defined cavities. Thereafter, hole(s) are formed in the netting and a blowing hose is inserted into the hole(s) for the purpose of filling the enclosed wall cavities with blown loose-fill siliconized fiberglass insulation. An exemplary insulation which may be used in conjunction with BIBS is InsulSafe III.TM. available from CertainTeed Corp., Valley Forge, Pa. This loose-fill fiberglass coated with a hydrophobic agent is said to be able to achieve an R-15 at a density of 2.5 lbs./ft.sup.3 when 3.5 inches thick. Perfect Fit.TM. loose-fill fiberglass available from Guardian Fiberglass, Albion, Mich. is another siliconized loose-fill often used (i.e. approved) in conjunction with BIBS.
In commercial BIBS applications, the loose-fill siliconized fiberglass may be blown using a commerically available Ark.Seal machine which coats the loose-fill with a liquid adhesive as the insulation is blown behind the netting or other (e.g. rigid) retaining structure. Unfortunately, the use of this liquid adhesive results in a number of problems, including: (i) the liquid adhesive often gums up the adhesive jet and/or hose thereby causing application and clean-up inefficiencies and hardships; (ii) storage and transport of the liquid adhesive to job sites are burdensome, costly, and render the liquid adhesive susceptible to freezing--the adhesive is damaged if frozen; (iii) user clean-up of the liquid adhesive equipment (i.e. hose, pump, nozzle, and environment) is time-consuming and cuts into potential production time (in contrast, a simple water system would require little clean-up); (iv) getting the proper adhesive/fiberglass mixture or ratio in the field (i.e. on site) is not as easy as it would seem--users are forced to manually mix the adhesive on site prior to use, this often leading to an improper (too much or too little) LOI (adhesive quantity) in the final blown insulation product which in turn creates a non-uniform application; and finally (v) users at the job site often may not make use of the required adhesive and simply spray water with the fiberglass in an attempt to save both time and money--this leading to a potentially inferior insulation product prone to settling after installation is complete.
U.S. Pat. Nos. 4,710,309 and 4,804,695 also disclose insulation blowing systems where the loose-fill is coated with a liquid adhesive prior to application and during the blowing process. Again, such systems suffer from the problems listed above which are inherent with the use of liquid adhesive.
It will be apparent from the above that there exists a need in the art for eliminating the need for the use of liquid adhesive. To date, no fiberglass product is commercially available for application with spraying/blowing applications which both eliminates the need for the liquid adhesive and provides satisfactory results with respect to uniformity, density, R-value, and LOI (loss-on-ignition).
As will be appreciated, insulation products are properly divided into two distinct categories: organic vs. inorganic. Fiberglass, an inorganic insulation product, has long been the insulation of choice among architects, builders, and contractors because it is non-moisture-absorbing, fire retardant, and provides consistently uniform R-values. In recent years, however, cellulose, an organic insulation product, has come into favor with many builders, particularly because of its cost and its use of natural products such as newspaper, cardboard, etc. (i.e. recyclability). Unfortunately, cellulose and its organic nature are generally viewed by many as undesirable in BIBS and other spray/blow applications for the following reasons: (i) its organic nature renders it attractive to mold, mildew, fungus, rodents, vermin, etc.; (ii) cellulose is penetrated by moisture (moisture does not simply coat the product as with fiberglass) rendering it susceptible to rot, decay, and requiring undesirably long cure times when exposed to liquid spray additives (especially in humid environments); (iii) cellulose often settles to a greater degree in cavities than, for example, fiberglass, thereby decreasing R-values within a filled cavity as time passes; (iv) cellulose is less aesthetically appealing to many users than fiberglass; and (v) cellulose is non-fire-resistant because of its organic nature and therefore requires an added chemical load for flame retardance purposes--this, of course, increasing cost and sometimes creating an unfriendly odor.
For example, U.S. Pat. No. 4,773,960 discloses a cellulose loose-fill insulation system (see also Suncoast's S.A.B..TM. System). Dry organic adhesive and cellulose-based insulation are sprayed or blown together with water which activates the adhesive during blowing. As set forth in the '960 patent, "insulation of the cellulose fiber type can be pre-treated with an adhesive which, when moistened, becomes activated and improves the setting properties of the insulation." Unfortunately, such cellulose pre-treated products are organic in nature and suffer from the inherent problems outlined above. Furthermore, the dry adhesive used to "pre-treat" the cellulose in the '960 patent as well as other cellulose systems is starch-based (i.e. organic). An actual adhesive disclosed in the '960 patent is wheat starch. Again, the organic nature of such pre-treating agents renders them susceptible to mold, mildew, fungus, rodents, vermin, etc., especially when in storage along with the cellulose prior to use.
It is also to be pointed out that many prior art fiberglass and cellulose products have high LOI values which leads to increased cost of product. It would satisfy a need in the art if a fiberglass system/product with a low LOI could be provided so as to improve yields while still resulting in uniform applications.
It will be apparent to those of skill in the art that a need exists in the art for a mixture including an inorganic insulation (e.g. fiberglass) and a dry inorganic adhesive for use in fiberglass spray systems which avoids the problems inherent in the pre-treated organic cellulose products discussed above thereby resulting in uniform and efficient product applications.
The term "LOI" (loss-on-ignition) as used herein is defined by ASTM C764-91, incorporated herein by reference. LOI refers to the known method for measuring the binder content of loose-fill mineral fiber insulation.